class_docstr: A representation of a node in the Tree
  Contains two main types of information:
      - Data relevant for the node
      - Links to children nodes
code: def update_y(self, y):
      self.data.update_y(y)
      if self.left_child is not None:
          self.left_child.update_y(y)
          self.right_child.update_y(y)
  
imports: from typing import Union, Tuple
  from .data import Data
  from .split import Split, SplitCondition
label_desc: Use image node_id 6 for calling the TreeNode obj's underlying member method code with example usage: obj.update_y(y) without return types